The present invention relates generally to low temperature liquid carbon dioxide cleaning systems and methods, enhanced by vigorous agitation methods, to displace insoluble soils off surfaces, emulsify, disperse and suspend these soils in a liquid carbon dioxide medium for transport and removal.
All cleaning and degreasing solvents currently used present health risks and are environmentally detrimental. For example, perchloroethylene is a suspected carcinogen, petroleum based solvents are flammable and smog producing, 1, 1, 1-trichloroethylene is known to deplete the earth's ozone layer and is scheduled for phase-out.
Liquid carbon dioxide is an inexpensive and unlimited natural resource, that is non-toxic, non-flammable, non-smog-producing or ozone-depleting. Liquid carbon dioxide does not damage fabrics, or dissolve common dyes, and exhibits solvating properties typical of hydrocarbon solvents. Its properties make it a good dry cleaning medium for fabrics and garments and industrial rags, as well as a good degreasing solvent for the removal of common oils and greases used in industrial processes, and a good liquid medium for insoluble soil suspension, dispersion and transport.
One disadvantage of the liquid carbon dioxide as a degreasing solvent is its reduced solvating capability compared to the common degreasing solvents. This deficiency has usually been addressed by the use of chemical additives or co-solvents. These additives increase the cost of operation and must be separated out for disposal, as part of solvent reclamation processing, further increasing operating costs.
Accordingly, it is an objective of the present invention to provide for a liquid carbon dioxide cleaning system and method at low temperatures, enhanced by vigorous mechanical agitation methods to displace, suspend, emulsify and transport the soil away from the substrates to be cleaned.